JP2017124837A - Synthetic resin cap - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synthetic resin cap capable of preventing breakage during capping.SOLUTION: A cap 1 comprises: a skirt wall 3 which comprises a female screw 5 screwed to a male screw formed on an outer periphery of a container mouth part; and a tamper-evident band 7 which is connected to a lower part of the skirt part 3 through an annular weakened part 6. On an inner peripheral side of the tamper-evident band 7, plural hooks 8 capable of engaging to an annular protrusion provided on the outer periphery of the container mouth part from a lower side, are provided with an interval in the peripheral direction. On an inner peripheral side of the tamper-evident band 7, a contact part 9 contacting an outer peripheral surface of the annular protrusion, is provided above the hooks 8. On the inner peripheral side of the tamper-evident band 7, a lower end of each hook 8 is positioned in a range within 1.0 mm from a lower end of the tamper-evident band 7.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a synthetic resin cap that is attached to the mouth of a container that contains contents such as beverages.

  2. Description of the Related Art As a cap that is attached to a mouth portion of a container that stores contents such as beverages, a cap that can be confirmed at a glance whether or not it is opened is widely used. As such a cap, a cap body having a skirt wall provided with a female screw to be engaged with a male screw of a container mouth portion, and a tamper evidence band connected to a lower portion of the skirt wall via an annular weakening portion It has been known.

  In the above conventional cap, a hook (locking protrusion) provided on the inner periphery of the tamper evidence band is provided on the outer periphery of the container mouth portion in accordance with the opening operation from the state of being attached to the container mouth portion. After locking to the (locking step portion), the bridge connecting the tamper evidence band and the skirt wall is broken, and the cap body and the tamper evidence band are separated from each other (see Patent Document 1). Therefore, by visually confirming whether or not the bridge is broken, it can be easily confirmed whether or not the opening operation has been performed.

JP2015-81103A

  However, in the conventional synthetic resin cap, there is a problem that the lower part of the tamper evidence band is relatively thin, and this part is easily bent and broken when capping the container mouth.

  The present invention has been made in consideration of the above-described matters, and an object of the present invention is to provide a synthetic resin cap capable of preventing breakage during capping.

  In order to achieve the above object, a synthetic resin cap according to the present invention comprises a skirt wall provided with a female screw that engages with a male screw formed on the outer periphery of a container mouth portion, and an annular weakening portion at a lower portion of the skirt wall. A tamper-evidence band connected via a hook, which is provided on the inner peripheral side of the tamper-evidence band with a hook that can be locked from below on an annular protrusion provided on the outer periphery of the container mouth. A plurality of the tamper-evidence bands are provided on the inner peripheral side of the tamper-evidence band, and a contact portion that contacts the outer peripheral surface of the annular protrusion is provided above the hook. On the inner peripheral side of the band, the lower end of the hook is located within 1.0 mm from the lower end of the tamper evidence band.

  In the synthetic resin cap, a plurality of through grooves extending from an upper part of the skirt wall to a lower part of the tamper evidence band are provided, and each through groove divides the female screw of the skirt wall, and between adjacent hooks. (Claim 2).

  In the synthetic resin cap, the hook may be provided with an odd number of seven or more (Claim 3).

  In this invention, the synthetic resin cap which can aim at the damage prevention at the time of capping is obtained.

  That is, in the synthetic resin cap according to each of the claims of the present application, when capping, the lower end portion of the tamper evidence band (the portion from the lower end of the tamper evidence band to the lower end of the hook) whose container mouth portion is relatively thin ), The lower end of the tamper-evidence band is short, so it is difficult to bend and break.

  In the synthetic resin cap according to the second aspect of the present invention, after molding of the cap, it is possible to suppress molding defects caused by forced removal from the mold.

  In the synthetic resin cap according to the third aspect of the present invention, the width of the hook and the protruding amount are suppressed to reduce the release resistance when forcibly removing from the mold, and the engagement with the annular protrusion on the outer periphery of the container mouth portion is reduced. It is possible to reliably stop the operation.

It is a longitudinal section showing roughly composition of a synthetic resin cap concerning one embodiment of the present invention. (A) is the bottom view which shows the structure of the said synthetic resin cap schematically, (B) is the B section enlarged view of (A). FIG. 3 is an end view taken along the line X-X in FIG. 2A, and the upper portion of the synthetic resin cap is not shown. It is an expanded view of the internal thread of the said synthetic resin cap.

  Embodiments of the present invention will be described below with reference to the drawings.

  A synthetic resin cap (hereinafter referred to as a cap) 1 shown in FIG. 1 and FIG. 2A is used by being attached to a mouth portion of a container (not shown) such as a PET bottle, for example, and compression molding or injection molding. Are integrally formed of polyethylene. In addition, the raw material which forms the cap 1 is not specifically limited, Polypropylene etc. other than the polyethylene used by this embodiment are used suitably.

  The cap 1 has a substantially circular top wall 2 in plan view, and a substantially cylindrical skirt wall 3 extending downward from the outer peripheral portion of the top wall 2. Here, a knurled groove 4 is provided on the outer peripheral surface of the skirt wall 3 and a female screw 5 is provided on the inner peripheral surface. The female screw 5 is coupled to a male screw (not shown) formed on the outer periphery of the container mouth. Is possible.

  The cap 1 is a pill fur-proof cap that has a function of proving that it has not been opened (that has never been opened), and the lower part of the skirt wall 3 has an annular weakening extending over the entire circumference of the skirt wall 3. A tamper evidence band (hereinafter, simply referred to as “band”) 7 is connected via a portion 6.

  In other words, the annular weakening 6 defines the skirt wall 3 and the band 7 up and down, and includes a slit (perforated) that extends intermittently in the circumferential direction of the skirt wall 3 and the band 7 and an adjacent slit. And the bridge breaks when pulled with a predetermined force.

  A plurality of hooks 8 (for example, nine) are provided on the inner peripheral side of the band 7 so as to protrude inward and to increase inward as the upper protrusion amount increases in the circumferential direction. It is. Each hook 8 is positioned substantially below an annular projection (bead portion) (not shown) formed below the male screw on the outer periphery of the container mouth portion with the cap 1 mounted on the container mouth portion. The operation is locked to the annular protrusion. That is, the hook 8 is configured to be able to be locked to the annular protrusion from below.

  In addition, on the inner peripheral side of the band 7, an abutting portion 9 that abuts on the outer peripheral surface of the annular protrusion in the process of mounting the container mouth portion is provided above the hook 8. The contact portion 9 extends in the circumferential direction of the band 7 and is continuously provided over the entire circumference. When the cap 1 attached to the container mouth is opened, the abutment portion 9 is brought into contact with the outer peripheral surface of the annular protrusion of the container mouth, so that the cap 1 is prevented from being lifted obliquely, and the annular weakening is performed. Since the portion 6 breaks substantially uniformly without being biased, the tamper evidence property is good.

  Further, on the inner peripheral side of the band 7, the lower end of the hook 8 is located within 1.0 mm from the lower end of the band 7. In other words, the distance from the lower end of the band 7 to the lower end of the hook 8 (distance in the axial direction of the band 7) d (see FIG. 3) is 1.0 mm or less, and the distance d in this example is 0.4 mm. . As a result, when the cap 1 is attached (capped) to the container mouth, the container mouth is in contact with the lower end of the band 7 (the portion from the lower end of the band 7 to the lower end of the hook 8) 7a where the container mouth is relatively thin. Even in this case, since the lower end portion 7a of the band 7 is short, it is bent inward and is not easily damaged. Moreover, as shown in FIG. 3, by providing a curved surface or inclined surface on the inner peripheral side of the lower end portion 7 a of the band 7, the inner diameter increases toward the tip end and decreases toward the hook 8. Since the curved surface or the inclined surface guides (centers) the container mouth portion to the inside of the band 7, it is possible to ensure the prevention of the damage.

  In addition, the shape from the contact portion 9 to the lower end portion 7a of the portion where the hook 8 is not provided on the inner peripheral surface of the band 7 extends straight up and down, as shown by a one-dot chain line in FIG. The vertical section of the hook 8 includes a longitudinal side 8a extending in the axial direction of the band 7, a lateral side 8b extending from the upper end of the longitudinal side 8a toward the inside of the band 7 and perpendicular to the longitudinal side 8a, the longitudinal side 8a and the lateral side. It has a substantially right triangle shape having a hypotenuse 8c connecting the sides 8b. The angle θ formed by the vertical side 8a and the oblique side 8c is 1 ° to 30 °, preferably 10 ° to 30 °, and is 20 ° in this example.

  On the other hand, the cap 1 of this example has a plurality of through grooves 10 extending from the upper part of the skirt wall 3 to the lower part of the band 7 as shown in FIG. 1, and each through groove 10 has an internal thread 5 of the skirt wall 3. It divides and extends so as to pass between adjacent hooks 8. Here, the female screw 5 is constituted by a screw thread that spirals around the inner peripheral surface of the skirt wall 3, and is divided at equal intervals in the circumferential direction by each through groove 10. That is, on the inner peripheral surface of the skirt wall 3, the through grooves 10 and the screw regions 12 where the thread pieces 11 separated by the through grooves 10 are alternately arranged in the circumferential direction.

  Here, the screw thread constituting the female screw 5 of this example is spirally wound around the inner peripheral surface of the skirt wall 3, and each screw region 12 has upper and lower two-stage thread pieces 11A and 11B. (See FIG. 4). In addition, one hook 8 is positioned below each screw region 12, the horizontal width of the upper thread piece 11A is the smallest, and the horizontal widths of the lower thread piece 11B and the hook 8 are substantially the same. The width of the piece 11B is slightly larger than the width of the hook 8. Further, the amount of protrusion from the inner peripheral surface of the skirt wall 3 is the same in the upper screw thread piece 11A and the lower screw thread side 11B, and the protrusion amount of the hook 8 is smaller than these protrusion amounts (FIG. 2). (See (A) and (B)).

  With such a configuration, after molding the cap 1 of this example, it is possible to suppress molding defects caused by forced removal from the mold. That is, when the cap 1 is molded, after the molten resin injected into the mold is cooled, the molded product is die-cut. The female screw 5 (thread piece 11) provided on the inner peripheral surface of the cap 1 Since the hook 8 is an undercut portion when the molded product is removed from the mold, in order to take out the molded product from the mold, the thread piece that is an undercut portion is discharged from the band 7 side of the molded product. 11 and the hook 8 need to be forcibly removed. And in the cap 1 of this example, since the position of the thread piece 11 used as an undercut part and the circumferential direction of the hook 8 is arrange | equalized in the inner peripheral surface of the cap 1, mold release resistance is made small comprehensively. As a result, molding defects are suppressed.

  Further, the number of hooks 8 provided on the band 7 is preferably an odd number of 7 or more and 19 or less, and is 9 in this example. Here, if the number of hooks 8 is 5 or less, the lateral width and the amount of protrusion required for each hook 8 in order to sufficiently engage the annular projection on the outer periphery of the container mouth portion become large, and the above-described separation. Increases mold resistance. Further, when the number of hooks 8 is 21 or more, it is difficult to give each hook 8 a sufficient lateral width and protrusion amount, and there is a possibility that locking to the annular protrusion on the outer periphery of the container mouth portion may be insufficient. . If the number of hooks 8 is an even number, portions where the hooks 8 do not exist are formed on the inner peripheral surface of the band 7, and this may weaken the locking force to the annular protrusion. Although this may occur, in this example, by using an odd number of hooks 8, the above-described portion is not formed, and the locking force to the annular protrusion is sufficiently maintained.

  In addition, this invention is not limited to said embodiment at all, Of course, it can change and implement variously in the range which does not deviate from the summary of this invention. For example, the following modifications can be given.

  In FIG. 4, the screw thread constituting the female screw 5 spirally wraps around the inner peripheral surface of the skirt wall 3, and each screw region 12 has two upper and lower thread pieces 11 </ b> A and 11 </ b> B. Although an example is shown, the number of turns of the screw thread constituting the female screw 5 may be less than two turns or more than two turns, and accordingly, the number of screw pieces 11 present in each screw region 12 is one. But three or more.

  FIG. 1 shows an example in which the lower thread piece 11B has a wider width than the upper thread piece 11A. However, the present invention is not limited to this, and for example, the widths of both 11A and 11B may be the same.

  FIG. 1 shows an example in which the female screw 5 is divided by the through groove 10, but the through screw 10 may be provided only in the band 7 without dividing the female screw 5.

  Although FIG. 1 shows an example in which the cap 1 is a so-called one-piece cap that does not have a separate packing, the cap 1 is not limited to this, and the cap 1 is a so-called two-piece cap having a separate packing. Also good.

  Although the internal thread 5 of the said embodiment is a triple thread, it is not restricted to this, The internal thread 5 may be a single thread, a double thread, etc.

  Needless to say, the above modifications may be combined as appropriate.

DESCRIPTION OF SYMBOLS 1 Cap 2 Top wall 3 Skirt wall 4 Knurled groove 5 Female screw 6 Annular weakening part 7 Band 8 Hook 8a Vertical side 8b Horizontal side 8c Slope side 9 Contact part 10 Through groove 11 Screw thread piece 11A Upper thread piece 11B Lower thread piece 12 Screw region θ angle

Claims (3)

A cap provided with a skirt wall provided with an internal thread that engages with an external thread formed on the outer periphery of the container mouth portion, and a tamper evidence band connected to the lower portion of the skirt wall via an annular weakening portion,
On the inner peripheral side of the tamper evidence band, a plurality of hooks that can be locked from below on annular protrusions provided on the outer periphery of the container mouth portion are provided at intervals in the circumferential direction,
Further, on the inner peripheral side of the tamper evidence band, a contact portion that contacts the outer peripheral surface of the annular protrusion is provided above the hook,
Furthermore, on the inner peripheral side of the tamper evidence band, the lower end of the hook is located within 1.0 mm from the lower end of the tamper evidence band.   A plurality of through-grooves extending from the upper part of the skirt wall to the lower part of the tamper-evidence band are provided, and each through-groove divides the female screw of the skirt wall and extends so as to pass between adjacent hooks. The synthetic resin cap according to claim 1.   The synthetic resin cap according to claim 1 or 2, wherein the hook is provided with an odd number of seven or more.

Images